Neoview Control Query Default (CQD) Reference Guide (R2.5)

Table of Contents
About This Document.........................................................................................................7
Supported Release Version Updates (RVUs)..........................................................................................7
Intended Audience.................................................................................................................................7
Document Organization.........................................................................................................................7
Notation Conventions.............................................................................................................................7
General Syntax Notation...................................................................................................................7
Publishing History..................................................................................................................................9
HP Encourages Your Comments............................................................................................................9
1 Introduction...................................................................................................................11
Overview of CQDs................................................................................................................................11
Setting CQDs.........................................................................................................................................12
Testing a CQD..................................................................................................................................12
Implementing a CQD......................................................................................................................12
2 Managing Adaptive Segmentation............................................................................13
DEFAULT_DEGREE_OF_PARALLELISM...........................................................................................13
PARALLEL_NUM_ESPS......................................................................................................................13
3 Managing Skew...........................................................................................................15
SKEW_EXPLAIN..................................................................................................................................15
SKEW_SENSITIVITY_THRESHOLD...................................................................................................15
4 Managing Automated STATS Generation.................................................................17
USTAT_AUTO_CV_SAMPLE_SLOPE.................................................................................................17
USTAT_AUTO_PRIORITY....................................................................................................................17
USTAT_MAX_READ_AGE_IN_MIN...................................................................................................18
USTAT_MIN_ROWCOUNT_FOR_SAMPLE.......................................................................................19
USTAT_NECESSARY_SAMPLE_MAX................................................................................................19
USTAT_OBSOLETE_PERCENT_ROWCOUNT...................................................................................20
5 Optimizer......................................................................................................................21
HASH_JOINS........................................................................................................................................21
JOIN_ORDER_BY_USER......................................................................................................................21
MDAM_SCAN_METHOD...................................................................................................................22
MERGE_JOINS.....................................................................................................................................22
NESTED_JOINS....................................................................................................................................23
OPTIMIZATION_LEVEL......................................................................................................................23
RISK_PREMIUM_NJ.............................................................................................................................24
RISK_PREMIUM_SERIAL....................................................................................................................25
ROBUST_QUERY_OPTIMIZATION....................................................................................................26
SUBQUERY_UNNESTING...................................................................................................................28
6 File Size and Placement (POS)...................................................................................29
POS_ABSOLUTE_MAX_TABLE_SIZE.................................................................................................29
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